Problem with login on AIX 5306

UNIX AIX
1

Hello Guys,
I am working on AIX 5306,when I ssh on to the server it just hangs.but I can still run commands remotely through ssh without logging in to the server.
I am not able to find out the problem,it's not only ssh even the telnet or normal login does not want to work it just hangs.when I reboot the system it is the same problem.To recover from this problem I actually have to shutdown the server and then startit back again.
I checked the error log and system logs but there are no problems found.I just found the following ether channel error
0 Mon Nov 19 03:05:48 USAST 2007 if_en: ns_alloc(en0) failed with errno = 19

Can plaese someone assist me with this problem
Thanks a lot
Noori

2

Please, provide us with more information such as:

  • errpt output.
  • syslog output.
  • software versions (ssh, openssl)
  • Explain in depth what "hang" means.
  • whatever could help us...
3

It looks like a problem with pseudo terminals....

Can you login using X and use xterm or dtterm?

4

Hello Grial,
The error report does not show any errors when this hang happens there is only a software program error for a core dump.I am placing it here anyways.

LABEL: CORE_DUMP
IDENTIFIER: 40E9A4E1

Date/Time: Thu Nov 22 19:43:45 USAST 2007
Sequence Number: 517808
Machine Id: 00CC86CC4C00
Node Id: za-pr-ap-fcdb1
Class: S
Type: PERM
Resource Name: SYSPROC

Description
SOFTWARE PROGRAM ABNORMALLY TERMINATED

Probable Causes
SOFTWARE PROGRAM

User Causes
USER GENERATED SIGNAL

    Recommended Actions
    CORRECT THEN RETRY

Failure Causes
SOFTWARE PROGRAM

    Recommended Actions
    RERUN THE APPLICATION PROGRAM
    IF PROBLEM PERSISTS THEN DO THE FOLLOWING
    CONTACT APPROPRIATE SERVICE REPRESENTATIVE

Detail Data
SIGNAL NUMBER
11
USER'S PROCESS ID:
7778364
FILE SYSTEM SERIAL NUMBER
1
INODE NUMBER
2
PROCESSOR ID
0
CORE FILE NAME
/core
PROGRAM NAME
licrmt

Syslog has been disabled so I don't get any syslogoutput from there.
but I get error reporting from the conslog and I have pasted that
0 Mon Nov 19 03:05:48 USAST 2007 if_en: ns_alloc(en0) failed with errno = 19
I don't know if this error is valid.

OSlevel is - 5300-06-02-0727
openssh - 4.3.0.5300

This server works fine but once in a while the users cannot login to the server thru telnet,ssh or whatever kind of login.I can ping the IP and I can see that the server is up and running.If I try to ssh in to the server as myself or any other user the session hangs indefinetely.
but I can run remote commands like the following from another server
ssh root@server1 lslpp -l | grep ssh.

Just for information there is an ether channel setup on this server.some of the hits suggested that the problem could be ether channnel and asked us to reconfigure the etherchannel and that we did.
In order for me to make this server normal I have to shutdown the server and bring it back again.
If I try to reboot the server it doesn't work.
I am facing this problem on 2 servers ,on one of the servers there is gpfs running and the version is 2.3.0.22.Please note that I already know the known issue of TL06 with gpfs 2.3.0.22.

but I don't think it is a gpfs problem since the other server does not have gpfs.
Please let me know if there is anything else that u need from me.

5

As someone pointed out, it looks to be a problem with the pseudo-terminal or some other necessary device. On one of the systems I have available, errno 19 is ENODEV (No such device), which may be caused by or the cause of the core dump (although I'm concerned that the core was left at /.

What if you run 'ssh server ls /dev'?

6

Hi,

I am working with Noori and have just tried increasing the nmber of pty's, with no joy.

To do so I used the command
"ssh za-pr-ap-fcdb1 " chdev -l pty0 -a ATTnum='500' "

and got the following result "pty0 changed"

When I try to ssh to the system it asks me for my password and then just hangs and goes no further.

We are able to scp files to and from the server successfully and run any non-interactive command. I have tried to access to the system from the hmc and by switching on telnet and telnetting. Neither work.

Any ideas?

7

download your self a copy of putty
use ssh and try to log in to the system and see if you still have problems

Have you confirmed that ssh are at the same level

There are a few things that can cause problems
but first test the basics

Other things to look at
APARTXT IY76807 = xauth hangs in certain conditions (ssh logins with X11)
NIS could cause hang or slow connections
System problems on the system can cause hang
Network problems